The present disclosure relates to a radiation image pickup apparatus suitable for, for example, X-ray photography for medical use and a non-destructive inspection, and to a radiation image pickup/display system including the apparatus.
In recent years, a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor has been largely used for acquiring an image as an electric signal (image pickup method using photoelectric conversion). An image pickup area of such an image sensor is limited by a size of a crystalline substrate (silicon wafer). However, increase in the image pickup area is demanded particularly in a medical field using X-rays for image pickup. In addition, high video performance is increasingly demanded in the medical field.
For example, the following radiation image pickup apparatus is used for a chest X-ray photography apparatus to directly generate electric signals as image data without using radiation photographic films. Specifically, in the radiation image pickup apparatus, a pixel section including photoelectric conversion elements such as photodiodes is provided on a substrate, and a wavelength conversion layer including a phosphor material is formed on the pixel section. In such a configuration, radiation is input to the apparatus and converted into visible light by the wavelength conversion layer, and then the visible light is received by each of the photoelectric conversion elements, and an electric signal corresponding to the amount of the received light is read out.
In such a radiation image pickup apparatus including the wavelength conversion layer, the phosphor material used for the layer deteriorates due to penetrated water, as generally known. In some proposed methods, a protective layer is provided over the wavelength conversion layer to seal the layer as disclosed in Japanese Patent Nos. 3029873 and 3077941, for example.